1. Field of the Invention
The present invention relates to warewashing machines and methods, and more particularly, but not by way of limitation, to low temperature chemical sanitizing type warewashing apparatus.
2. Description of the Prior Art
In a typical low temperature chemical sanitizing type warewasher, a wash and rinse tank is filled with hot water at approximately 140° F. A rack of dishes is inserted in the washer and then the washer door is closed which actuates the wash cycle. A wash and rinse pump turns on to circulate the wash water from the tank to spray devices to wash the dishes. During the wash cycle detergent is pumped into the wash and rinse tank. After the wash cycle a solenoid drain valve opens to drain the wash and rinse tank. Wash water and food soil is dumped into a drain pan where it passes through a screen to an accumulator. Then, a fill valve opens and flushes the wash and rinse tank while the drain valve is open. The drain valve closes and the wash and rinse tank fills to an appropriate level and the fill valve closes. Sanitizer such as sodium hypochlorite and rinse additive are pumped into the wash and rinse tank. The wash and rinse pump again turns on and the dishes are rinsed. The wash and rinse pump then turns off and the cycle is complete. The rinse water is retained in the wash and rinse tank for use in the next wash cycle. The process is repeated for each successive rack of dishes or other tableware.
The typical low temperature chemical sanitizing warewasher machine does not include a heater in the wash and rinse tank. Thus if the machine is idle for an extended period of time the wash tank temperature will fall. If the operator does not manually drain and refill the tank before using the machine after an idle period, the machine will wash with water that is cooler than normal for proper operation. The typical outcome of this is a poor wash result from the warewasher.